Genetic Associations Between Modifiable Risk Factors and Alzheimer Disease
Authors: Jiao Luo, Jesper Qvist Thomassen, Céline Bellenguez, Benjamin Grenier-Boley, Itziar de Rojas, Atahualpa Castillo, Kayenat Parveen, Fahri Küçükali, Aude Nicolas, Oliver Peters, Anja Schneider, Martin Dichgans, Dan Rujescu, Norbert Scherbaum, Deckert Jürgen, Steffi Riedel-Heller, Lucrezia Hausner, Laura Molina Porcel, Emrah Düzel, Timo Grimmer, Jens Wiltfang, Stefanie Heilmann-Heimbach, Susanne Moebus, Thomas Tegos, Nikolaos Scarmeas, Jordi Clarimon, Fermin Moreno, Jordi Pérez-Tur, María J. Bullido, Pau Pastor, Raquel Sánchez-Valle, Victoria Álvarez, Mercè Boada, Pablo García-González, Raquel Puerta, Pablo Mir, Luis M. Real, Gerard Piñol-Ripoll, Jose María García-Alberca, Jose Luís Royo, Eloy Rodriguez-Rodriguez, Hilkka Soininen, Teemu Kuulasmaa, Alexandre de Mendonça, Shima Mehrabian, Jakub Hort, Martin Vyhnalek, Sven van der Lee, Caroline Graff, Goran Papenberg, Vilmantas Giedraitis, Anne Boland, Delphine Bacq-Daian, Jean-François Deleuze, Gael Nicolas, Carole Dufouil, Florence Pasquier, Olivier Hanon, Stéphanie Debette, Edna Grünblatt, Julius Popp, Luisa Benussi, Daniela Galimberti, Beatrice Arosio, Patrizia Mecocci, Vincenzo Solfrizzi, Lucilla Parnetti, Alessio Squassina, Lucio Tremolizzo, Barbara Borroni, Benedetta Nacmias, Sandro Sorbi, Paolo Caffarra, Davide Seripa, Innocenzo Rainero, Antonio Daniele, Carlo Masullo, Gianfranco Spalletta, Julie Williams, Philippe Amouyel, Frank Jessen, Patrick Kehoe, Magda Tsolaki, Giacomina Rossi, Pascual Sánchez-Juan, Kristel Sleegers, Martin Ingelsson, Ole A. Andreassen, Mikko Hiltunen, Cornelia Van Duijn, Rebecca Sims, Wiesje van der Flier, Agustín Ruiz, Alfredo Ramirez, Jean-Charles Lambert, Ruth Frikke-Schmidt
Journal: JAMA Network Open (2023)

Importance An estimated 40% of dementia is potentially preventable by modifying 12 risk factors throughout the life course. However, robust evidence for most of these risk factors is lacking. Effective interventions should target risk factors in the causal pathway to dementia. Objective To comprehensively disentangle potentially causal aspects of modifiable risk factors for Alzheimer disease (AD) to inspire new drug targeting and improved prevention. Design, Setting, and Participants This genetic association study was conducted using 2-sample univariable and multivariable mendelian randomization. Independent genetic variants associated with modifiable risk factors were selected as instrumental variables from genomic consortia. Outcome data for AD were obtained from the European Alzheimer &amp;amp;amp; Dementia Biobank (EADB), generated on August 31, 2021. Main analyses were conducted using the EADB clinically diagnosed end point data. All analyses were performed between April 12 and October 27, 2022. Exposures Genetically determined modifiable risk factors. Main Outcomes and Measures Odds ratios (ORs) and 95% CIs for AD were calculated per 1-unit change of genetically determined risk factors. Results The EADB-diagnosed cohort included 39 106 participants with clinically diagnosed AD and 401 577 control participants without AD. The mean age ranged from 72 to 83 years for participants with AD and 51 to 80 years for control participants. Among participants with AD, 54% to 75% were female, and among control participants, 48% to 60% were female. Genetically determined high-density lipoprotein (HDL) cholesterol concentrations were associated with increased odds of AD (OR per 1-SD increase, 1.10 [95% CI, 1.05-1.16]). Genetically determined high systolic blood pressure was associated with increased risk of AD after adjusting for diastolic blood pressure (OR per 10–mm Hg increase, 1.22 [95% CI, 1.02-1.46]). In a second analysis to minimize bias due to sample overlap, the entire UK Biobank was excluded from the EADB consortium; odds for AD were similar for HDL cholesterol (OR per 1-SD unit increase, 1.08 [95% CI, 1.02-1.15]) and systolic blood pressure after adjusting for diastolic blood pressure (OR per 10–mm Hg increase, 1.23 [95% CI, 1.01-1.50]). Conclusions and Relevance This genetic association study found novel genetic associations between high HDL cholesterol concentrations and high systolic blood pressure with higher risk of AD. These findings may inspire new drug targeting and improved prevention implementation.